1,721,005 research outputs found
COX-2 overexpression in canine tumors: potential therapeutic targets in oncology
No full textCyclooxygenases catalyze the initial, rate-limiting steps of prostaglandin synthesis from arachidonic acid. Two isoforms of this enzyme exist in mammalian and avian species: COX-1 and COX-2. COX-1 is constitutively expressed and is the major isoform of gastrointestinal tissue. COX-2 is induced in response to inflammatory stimuli. COX-2 has been implicated in carcinogenesis of several neoplasms. Furthermore, COX-2 over-expression has been noted in many solid tumours and has been correlated with a worse prognosis in colorectal cancer, non-small-cell lung cancer, mesothelioma and gastric cancer. In this review, the most recent findings on the mechanisms by which COX-2 promote tumorigenesis are discussed, with particular emphasis on the studies involving spontaneous canine neoplasms
Input Perturbation Reduces Exposure Bias in Diffusion Models
Full text linkDenoising Diffusion Probabilistic Models have shown an impressive generation quality although their long sampling chain leads to high computational costs. In this paper, we observe that a long sampling chain also leads to an error accumulation phenomenon, which is similar to the exposure bias problem in autoregressive text generation. Specifically, we note that there is a discrepancy between training and testing, since the former is conditioned on the ground truth samples, while the latter is conditioned on the previously generated results. To alleviate this problem, we propose a very simple but effective training regularization, consisting in perturbing the ground truth samples to simulate the inference time prediction errors. We empirically show that, without affecting the recall and precision, the proposed input perturbation leads to a significant improvement in the sample quality while reducing both the training and the inference times. For instance, on CelebA 64×64, we achieve a new state-of-the-art FID score of 1.27, while saving 37.5% of the training time. The code is available at https://github.com/forever208/DDPM-IP
Variability in Crithmum maritimum L. Essential Oils’ Chemical Composition: PCA Analysis, Food Safety, and Sustainability
Full text linkIn this study, four accessions of Crithmum maritimum L., not previously studied, collected in Isola delle Femmine (Italy) (S43), Croatia (S44), Montenegro (S45), and Israel (S46) were investigated. The volatile profile of essential oils was evaluated using GC–MS and 38 compounds were identified. All the analyzed samples show a composition characterized essentially by monoterpene hydrocarbons (94.0–97.6%), with limonene, γ-terpinene, β-phellandrene, α-pinene, and p-cymene as the principal compounds. In addition, a comprehensive review of the composition of C. maritimum essential oils that have been studied thus far was conducted. To evaluate the similarity between samples, principal component analysis (PCA) and Hierarchical Cluster Analysis (HCA) were utilized. To evaluate the possibility of addressing food value to natural species that can strengthen sustainable food policies, it appears necessary to consider the previous safety of the dietary intake of C. maritimum. A matrix plot analysis of the content of dillapiole, a toxic constituent, in the samples was performed. The results of the statistical analysis show the presence of six clusters indicating some differences between C. maritimum accessions from different locations. Regarding dillapiole content, the four accessions discussed in this paper showed dillapiole values of less than 2%, suggesting the healthiness of sea fennel from these locations, while the highest values were found in samples from France, Portugal, and Tunisia
A Graph-Based Multi-Scale Approach With Knowledge Distillation for WSI Classification
No full textThe usage of Multi Instance Learning (MIL) for classifying Whole Slide Images (WSIs) has recently increased. Due to their gigapixel size, the pixel-level annotation of such data is extremely expensive and time-consuming, practically unfeasible. For this reason, multiple automatic approaches have been raised in the last years to support clinical practice and diagnosis. Unfortunately, most state-of-the-art proposals apply attention mechanisms without considering the spatial instance correlation and usually work on a single-scale resolution. To leverage the full potential of pyramidal structured WSI, we propose a graph-based multi-scale MIL approach, DAS-MIL. Our model comprises three modules: i) a self-supervised feature extractor, ii) a graph-based architecture that precedes the MIL mechanism and aims at creating a more contextualized representation of the WSI structure by considering the mutual (spatial) instance correlation both inter and intra-scale. Finally, iii) a (self) distillation loss between resolutions is introduced to compensate for their informative gap and significantly improve the final prediction. The effectiveness of the proposed framework is demonstrated on two well-known datasets, where we outperform SOTA on WSI classification, gaining a +2.7% AUC and +3.7% accuracy on the popular Camelyon16 benchmark
The essential oil chemical composition of the aerial parts of Asparagus pastorianus Webb & Berthel growing wild in Sicily (Italy)
No full textThe genus Asparagus L. (Asparagaceae) has a wide geographical distribution being present in Europe, Africa, and Asia to N. Australia. The use of Asparagus ssp. dates since Ancient Grecians and Romans and several ethnopharmacological properties have been reported for many species. Asparagus pastorianus Webb & Berthel is a taxon described for the flora of the Canary Islands. The species is also reported in northern Morocco. Recently it has also been included in the Italian flora as present in southern Sicily. In this study, the chemical composition of the essential oil from aerial parts (Ap) of a Sicilian accession of this plant, never previously investigated, was evaluated by GC-MS. The essential was characterised by large amounts of aldehydes (65.5%) and alkanes (19.3%) whereas terpenes were very poorly represented. An update of all the essential oils of Asparagus species, studied so far, was carried out
Exploring Sicilian accession of Daucus muricatus (L.) L.: chemical composition of flower and root’s essential oils
No full textDaucus L. (Apiaceae) is a genus distributed worldwide, with the Mediterranean area serving as the centre of its diversity. Daucus muricatus (L.) L. is an annual plant growing primarily in the temperate biome. For the first time, in this research the chemical composition of the essential oil (EO) from flowers and roots of a Sicilian accession of this plant, was evaluated by GC–MS. An update of all the EOs of the Daucus species was carried out and compared to these data the volatile profile of the EO obtained from the Sicilian accessions of D. muricatus is rather particular. Flower and root EOs (Dmf and Dmr, respectively) showed alkanes as the main class, accounting for 27.2% and 60.0%, respectively. Both EOs were also characterised by the presence of alloaromadendrene oxide (15.6% in Dmr and 11.5% in Dmf). Dmf also showed a good amount of sabinene (11.6%), which is totally absent in Dmr
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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